title: Flexural strengths of conventional and nanofilled fiber-reinforced composites: a three-point bending test.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of the introduction of nanofillers on the mechanical properties of fiber-reinforced composites (FRCs) for stabilization and conservative treatment of multiple traumatized anterior teeth. In particular, the aim of the research was to point out the force levels of two sizes (diameters 0.6 and 0.9 mm) of both conventional and nanofilled FRCs.
  
  
  METHODS
  Eighty FRCs samples were divided into eight groups, each consisting of 10 specimens. Conventional (groups 1, 2, 3, and 4) and nanofilled (groups 5, 6, 7, and 8) FRC samples were evaluated. Each FRC was tested in two diameters (0.6 and 0.9 mm) and under two deflections (1 and 2 mm). Each sample was polymerized with the same halogen curing unit and then evaluated with a 3-point bending test on a universal testing machine after 48 h of dry storage.
  
  
  RESULTS
  Nanofilled FRCs showed significantly higher load values than conventional FRCs. Moreover, 0.9-mm-diameter FRCs showed significantly higher load value than 0.6-mm-diameter FRCs. Specimens tested at 2-mm deflection showed significantly higher load values than those tested at 1-mm deflection.
  
  
  CONCLUSIONS
  Nanofilled FRCs showed significantly higher load values than conventional FRCs. Higher flexural strength values were recorded with 1-mm deflection for both FRC tested.
authors.affiliation: Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Unità di Odontostomatologia, Reparto di Ortognatodonzia, University of Pavia, Pavia, Italy.
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Sfondrini
authors.forename: Sarah
authors.initials: S
authors.lastname: Massironi
authors.forename: Giulia
authors.initials: G
authors.lastname: Pieraccini
authors.forename: Andrea
authors.initials: A
authors.lastname: Scribante
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
authors.forename: Lippo V
authors.initials: LV
authors.lastname: Lassila
authors.forename: Paola
authors.initials: P
authors.lastname: Gandini
mesh_terms: D000180:Acrylic Resins / Q000032:analysis* / Q000627:therapeutic use; D003188:Composite Resins / Q000032:analysis* / Q000627:therapeutic use; D006801:Humans; D008422:Materials Testing; D053761:Nanocomposites / Q000032:analysis* / Q000627:therapeutic use; D011140:Polyurethanes / Q000032:analysis* / Q000627:therapeutic use
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes
keywords: dentistry; fiber-reinforced composite; flexural strength; nanofilled FRC; nanofiller; orthodontics